The present disclosure relates to an image forming apparatus, such as a copy machine, a printer, a facsimile, or the like, including an image carrier and a transfer roller that transfers a toner image formed on the image carrier onto a recording medium.
Conventionally, in an image forming apparatus employing an electrophotographic process, the following method has generally been adopted. That is, an electrostatic latent image is formed on an image carrier (photosensitive drum) whose surface is uniformly charged, and by use of a developing unit, a toner image based on the electrostatic latent image is formed on the image carrier. Then, by use of a transfer member, such as a transfer roller, that forms a transfer nip portion between itself and the photosensitive drum, the toner image formed on the image carrier is transferred onto a paper sheet that is conveyed to the transfer nip portion, after which the paper sheet is passed through a fixing unit so that the toner image is fixed on the paper sheet.
There is known a configuration in which a developing unit is mountable/demountable with respect to a main body of an image forming apparatus. In a case of occurrence of a paper jam inside the image forming apparatus, a developing device is demounted from the image forming apparatus so that a jammed paper sheet can be removed. Furthermore, the developing unit includes a contact point that allows the developing unit to be mounted in either of two types of image forming apparatuses different in mounting/demounting direction of an imaging cartridge (developing unit), and thus whether the developing unit is mounted in one or the other of these two types of image forming apparatuses, electrical connection to a contact point member of the one or the other of these types of image forming apparatuses can be performed with reliability.